Apparatus and method for coupling work tool to a machine

ABSTRACT

An apparatus to couple a work tool to an arm assembly is disclosed. The arm assembly may have a first arm and a second arm. The work tool may have a first recess and a second recess. The apparatus may have a first pin that may engage with the first arm and the first recess. The apparatus may have a second pin that may engage with the second arm and the second recess. The apparatus may have an actuator coupled to the first pin and second pin. The actuator may move between a retracted position and an extended position. The apparatus may have a locking sleeve mounted at least partially around the actuator. The locking sleeve may be moveable into a locked position to prevent the actuator from moving into the retracted position from the extended position.

TECHNICAL FIELD

The present disclosure relates to engaging work tools to machines, andmore particularly it relates to an apparatus and a method for assemblinga work tool to an arm assembly of a machine.

BACKGROUND

Machines, such as, hydraulic excavators, hydraulic shovels, backhoeloaders and the like, are often required to perform different kinds ofwork on a work site. Therefore, different work tools, such as buckets,hammers, rippers, and grapples, may have to be engaged with an armassembly (including for example, sticks and booms) of the machine. It isknown that the process of removing one work tool from the arm assemblyand replacing the work tool with a different work tool may be a timeconsuming and difficult process. Quick couplers have been employed toenable quick engagement of the stick and the work tool and the quickcouplers do, to an extent, reduce effort required for removing the worktool and replacing it. However, such quick couplers add weight to thestick end and build up the stick height/length. As a result, themachine's capabilities may be compromised.

For example, U.S. Pat. No. 5,400,531 A discloses an excavator orearth-working device. The earth working device includes a forked dipperarm, a linkage and an earth-working implement pivotally connected to theforked dipper arm and linkage. The implement is attached to a dipper armand linkage of the earth-working device by a so-called “quick-hitch”connection to allow interchange between various earth-workingimplements. A safety device may also be provided on the “quick-hitch”connection to prevent accidental detachment of the implement from thedipper arm and linkage.

SUMMARY OF THE DISCLOSURE

The present disclosure provides an apparatus for coupling a work tool toan arm assembly of a machine. The work tool includes first and secondtool engagement means and the arm assembly includes first and secondarms. Further, the apparatus includes a first coupling means adapted toengage with the first arm and the first tool engagement means. Theapparatus further includes a second coupling means adapted to engagewith the second arm and the second tool engagement means. The apparatusalso includes an actuator coupled to and arranged to move the first andsecond coupling means between a retracted position, in which the firstand/or second coupling means is disengaged from the first and/or secondtool engagement means, and an extended position, in which the first andsecond coupling means are engaged with the first and second toolengagement means. Further, a locking sleeve is mounted at leastpartially around the actuator, the locking sleeve being moveable into alocked position to prevent the first and second coupling means frommoving into the retracted position from the extended position.

The present disclosure further provides a machine comprising theaforementioned apparatus. In a further embodiment, the presentdisclosure may further provide an arrangement comprising aforementionedapparatus, arm assembly and work tool.

The present disclosure further provides a method of coupling a work toolto an arm assembly of a machine. The work tool having first and secondtool engagement means and the arm assembly having first and second arms.The method includes engaging a first coupling means with the first armand the first tool engagement means. The method includes engaging asecond coupling means with the second arm. The method further includesmoving an actuator to an extended position to engage the second couplingmeans to the second tool engagement means. The method also includesmoving a locking sleeve to a locked position to prevent the first andsecond coupling means from moving into the retracted position from theextended position.

Other features and aspects of this disclosure will be apparent from thefollowing description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a side view of a machine equipped with an armassembly, according to an embodiment of the present disclosure;

FIG. 2 illustrates the arm assembly equipped with a coupling apparatusfor assembling a work tool to the arm assembly in a retracted position,according to an embodiment of the present disclosure;

FIG. 3 illustrates a coupling apparatus, according to an embodiment ofthe present disclosure;

FIG. 4 illustrates the coupling apparatus, according to an embodiment ofthe present disclosure;

FIG. 5 illustrates a locking sleeve of the coupling apparatus, accordingto an embodiment of the present disclosure;

FIG. 6 illustrates a locking sleeve disposed over an actuator, accordingto an embodiment of the present disclosure;

FIG. 7 illustrates a cross sectional view of the locking sleeve disposedover an actuator;

FIG. 8 illustrates an operation to couple or assemble the toolengagement means and the arm assembly, according to an embodiment of thepresent disclosure;

FIG. 9 illustrates an operation to couple or assemble the toolengagement means and the arm assembly, according to an embodiment of thepresent disclosure;

FIG. 10 illustrates an operation to couple or assemble the toolengagement means and the arm assembly, according to an embodiment of thepresent disclosure;

FIG. 11 illustrates the arm assembly equipped with an apparatus forassembling a work tool to the arm assembly, according to an embodimentof the present disclosure; and

FIG. 12 is a flowchart of a method of assembling the tool engagement tothe arm assembly, according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to specific embodiments orfeatures, examples of which are illustrated in the accompanyingdrawings. Wherever possible, corresponding or similar reference numberswill be used throughout the drawings to refer to the same orcorresponding parts. Moreover, references to various elements describedherein, are made collectively or individually when there may be morethan one element of the same type. However, such references are merelyexemplary in nature. It may be noted that any reference to elements inthe singular may also be construed to relate to the plural andvice-versa without limiting the scope of the disclosure to the exactnumber or type of such elements unless set forth explicitly in theappended claims.

FIG. 1 illustrates a side view of an exemplary machine 100 equipped withan arm assembly 102, according to an embodiment of the presentdisclosure. The machine 100 may be an excavator, a material handler, along reach excavator, a foundation drill, a rock drill, a pilingmachine, a tunneling machine, or a front shovel. In the illustratedembodiment, the machine 100 is shown to be an excavator-type earthmovingor logging machine. Further, the arm assembly 102 includes linkages suchas a boom 104, at least one arm, such as a first arm 106, and a worktool 108. The boom 104 may be pivotally connected to a chassis 110 ofthe machine 100, the first arm 106 may be pivotally connected to theboom 104, and the work tool 108 may be pivotally connected to the firstarm 106.

The machine 100 may also include a ground engaging unit 112, such astracks for propelling the machine 100, a power source 114 to power thearm assembly 102 and the ground engaging unit 112, and an operator cabin116 for hosting user interface devices for controlling the arm assembly102 and the ground engaging unit 112. The power source 114 may includean engine, such as a diesel engine, a gasoline engine, a gaseousfuel-powered engine, or any other type of combustion engine known in theart. The power source 114 may alternatively embody a non-combustionsource of power such as a fuel cell, a power storage device, or anothersource known in the art. The power source 114 may produce a mechanicalor electrical power output that may then be converted to hydraulic powerfor moving the arm assembly 102 and the work tool 108.

Further, an overall movement of the work tool 108 in a first verticalplane 118 (shown in FIG. 1) may be achieved in three parts, first byraising and lowering the boom 104 with respect to the chassis 110,second by moving the first arm 106 toward and outward with respect tothe operator cabin 116, and third by rotating the work tool 108 relativeto the first arm 106. The boom 104 may be raised and lowered by a pairof first hydraulic actuators 120. The first arm 106 may be moved towardand outward with respect to the operator cabin 116 by a second hydraulicactuator 122. In addition, a third hydraulic actuator 124 may be used toturn the work tool 108 relative to the first arm 106. Furthermore, thechassis 110 and the arm assembly 102 may be rotated about a verticalaxis A-A′ (shown in FIG. 1) by a fourth hydraulic actuator 126, such asa hydraulic motor, with respect to the ground engaging unit 112.According to an aspect of the present disclosure, the machine 100includes a coupling apparatus 128 for coupling the work tool 108 to thearm assembly 102 and to aid in the turning movements of the work tool108 with respect to the first arm 106.

FIG. 2 illustrates the arm assembly 102 and the coupling apparatus 128operably coupled to the arm assembly 102, in accordance with anembodiment of the present disclosure. As described earlier, the armassembly 102 includes the first arm 106, which extends longitudinallyaway from the operator cabin 116. In one example and for the purpose ofthis description, the first arm 106 is considered to have a rectangularcross-section, and accordingly the first arm 106 has a first side 202and a second side (not shown) opposite to the first side 202. Further,the arm assembly 102 includes a first connecting arm 204 and a secondconnecting arm 206. The first connecting arm 204 has a first end 208 anda second end 210. The first end 208 of the first connecting arm 204 isadapted to be attached to the first side 202 of the first arm 106 andthe second end 210 of the first connecting arm 204 is disposed distantfrom the surface of the first arm 106. Similarly, the second connectingarm 206 has a first end 212 and a second end 214. The first end 212 ofthe second connecting arm 206 is adapted to be attached to the secondside of the first arm 106 and the second end 214 of the secondconnecting arm 206 is disposed distant from the surface of the first arm106. In one example, the first connecting arm 204 and the secondconnecting arm 206 may be positioned inclined with a certain angle withrespect to the first arm 106.

The arm assembly 102 may further include a second arm 216 having a firstend 218 and a second end 220. The first end 218 of the second arm 216 isattached to the second end 210 of the first connecting arm 204 and thesecond end 214 of the second connecting arm 206. Further, the second end220 of the second arm 216 is disposed distant from the first end 218;such that the second arm 216 is inclined to the first connecting arm 204and the second connecting arm 206. In an embodiment of the presentdisclosure, the first arm 106 may be a stick end of the arm assembly102, and the second arm 216 may be a push bar.

For the purpose of coupling the coupling apparatus 128 to the armassembly 102, the arm assembly 102 includes at least one mounting means,such as a first mounting means 222 and a second mounting means 224. Insaid implementation, the first mounting means 222 is located at thefirst side 202 of the first arm 106, as shown in FIG. 2. The secondmounting means 224 is located at the second end 220 of the second arm216. The first mounting means 222 and the second mounting means 224 maybe, for example, includes passageways formed in, for example, hollowcylindrical components.

In construction, as illustrated in FIG. 2, the work tool 108 includes atleast one tool engagement means, such as a first tool engagement means226 and a second tool engagement means 227. The present embodimentincludes a pair of first tool engagement means 226 and a pair of secondtool engagement means 227. The first tool engagement means 226 and thesecond tool engagement means 227 are adapted to be coupled to the firstmounting means 222 and the second mounting means 224 respectively. Thefirst and second tool engagement means 226, 227 may includes recesseslocated on side plates 232 and 233 respectively. In particular, eachside plate 232, 233 may include a pair of inwardly facing hooks formingthe recesses. Thus the openings of the recesses forming the first toolengagement means 226 may face the openings of the recesses forming thesecond tool engagement means 227. The side plate 232 and side plate 233are attached to a base member 234. Further, the base member 234 isadapted to be attached to the work tool 108. In one example, the basemember 234 may be welded to the work tool 108. In another example, thefirst and second tool engagement means 226, 227 may be formed as anintegral part of the work tool 108. However, the tool engagement means226, 227 may be attached to the work tool 108 in various other ways, aswould be known to a person skilled in the art, albeit with fewvariations to the structure of the first and second tool engagementmeans 226, 227 and the work tool 108 illustrated in FIG. 2.

FIGS. 3-5 illustrate the coupling apparatus 128, according to theembodiment of the present disclosure. Reference may also be made to FIG.2 to describe one or more components of the work tool 108. The couplingapparatus 128 includes an actuator 240. The actuator 240 includes afirst member 242 and a second member 244. Further, the actuator 240defines a longitudinal axis B-B′ that passes through the center of thefirst and second member 242, 244, as shown in FIGS. 3 and 4. In thepresent embodiment, the first member 242 is circular in cross section.Alternately, the first member 242 can square or rectangle or any othershape according to requirement. The first member 242 includes a firstend 246 and second end 248 distal, and separated along axis B-B′, fromthe first end 246. The first end 246 of the first member 242 is providedwith a hole 230. The hole 230 is disposed perpendicular to thelongitudinal axis B-B′ as shown in FIG. 3.

The first member 242 includes an outer surface 250 that extends from thefirst end 246 to the second end 248. The outer surface 250 includes oneor more stops 252. In the present example, the outer surface 250disposes a pair of stops 252 proximal to the second end 248. Also, thestops 252 are square extrusions. Alternately, there may be multiplestops 252 in any location on the outer surface 252 of circular,rectangular or of any other shape, according to the design requirements.Each stop 252 extends radially perpendicular to the outer surface 250 ofthe first member 242. The first member 242 further includes a passageway254 extending therein from the second end 248 as shown. The passageway254 is disposed such that the longitudinal axis B-B′ passes through acenter of the passageway 254 as shown. In the present disclosure, thepassageway 254 is a circular hole. Alternately, the passageway 254 maybe a square, rectangular hole or a hole of any other cross sectionaccording to the design requirements.

As best shown in FIG. 4, the second member 244 extends between a firstend 256 and a second end 258. The second end 258 of the second member244 is distal to and separated along longitudinal axis B-B′ from thefirst end 256. In the present embodiment, the second member 244 includesan elongate body 245. In an example the elongate body 245 is cylindricaland substantially round in cross section. In another, example theelongate body 245 can be square rectangle or any other shape accordingto the design requirements. The elongate body 245 includes a series ofdifferent diameters along axis B-B′ between the first end 256 and thesecond end 258. The elongate body 245 includes a first portion 260having uniform diameter, a second portion 262 of a larger uniformdiameter connected to the first portion 260 and a third portion 264 ofyet a larger uniform diameter connected to the second portion 262.

In particular, the first portion 260 has a diameter D1 about thelongitudinal axis B-B′ along a length L1 along the longitudinal axisB-B′. The second portion 262 has a diameter D2 about the longitudinalaxis B-B′ and a length L2 in the longitudinal direction axis B-B′. Thethird portion 264 extends between the second portion 262 and the secondend 258 with a diameter D3 about the longitudinal axis B-B′ and lengthL3. In the illustrated embodiment L2 is greater than L3 and L3 isgreater than L1, although in alternative embodiments the lengths L1, L2,L3 may be equal or different. In the illustrated embodiment D3 isgreater than D2 and D2 is greater than D1, although in alternativeembodiments the diameters D1, D2, D3 may be equal or different.

The first and second members 242, 244 are coupled together. Asillustrated in FIG. 6, the passageway 254 of the first member 242slidably receives the second portion 262 and the third portion 264 ofthe second member 244. The diameter “D3” of the third portion 264 thatextends radially from the diameter “D2” of the second portion 262 abutswithin a protrusion within the passageway 254. Further, the secondmember 244 can be relatively displaced along the length L2 of the secondportion 262 within the passageway 254. In an example, the relativedisplacement between the first and second member 242, 244 may be carriedout in any way known in the art, such as manually, hydraulically ormagnetically.

Referring to FIGS. 5 to 10, the coupling apparatus 128 further includesa locking sleeve 270. The locking sleeve 270 is mounted over theactuator 240. The locking sleeve 270 includes a first portion 272 and asecond portion 274 extending from the first portion 272. The firstportion includes a home 271 therethrough (illustrated in FIG. 5). Thehome 271 receives the first portion 260 of the second member 244,allowing the locking sleeve 270 to turn about the longitudinal axisB-B′. The second portion 274 includes one or more protrusions 276 thatextend along the longitudinal axis B-B′ from the first portion 272. Inthe present embodiment, the protrusions 276 dispose a pair of first slot275 and a second slot 278. The first slot 275 is configured to receivethe stops 252 when the second portion 262 is partially or completelyreceived within the passageway 254. The second slot 278 is disposeddistal to the first portion 272. The second slot 272 is shaped toreceive the stops 252 when the second portion 262 extends from thepassageway 254.

The actuator 240 is arranged to move the first and second coupling means228, 230 between extended and retracted positions as shown in FIG. 2 andFIGS. 8 to 10 by moving the first and second members 242, 244 relativeto one another. In an example the retracted position the second portion262 is partially or completely received within the passageway 254, asshown in FIG. 2. In the retracted position, at least one of the holes228, 230 is disengaged from the first and/or second tool engagementmeans 226, 227. In the extended position, the second portion 262 ispartially or completely extends out of the passageway 254.

The coupling apparatus 128 includes a first coupling means 236 and asecond coupling means 238. The first coupling means 236 is adapted toengage with the first arm 106 and the first tool engagement means 226.The second coupling means 238 is adapted to engage with the second arm216 and the second tool engagement means 227. In the present disclosure,the first coupling means 236 is a pin member for coupling the first toolengagement means 226 with the hole 228 of the second member 244 and thefirst mounting means 222 of the first arm 106. The second coupling means238 is a pin member for coupling the second tool engagement means 227with the second mounting means 224 of the second arm 216 and the hole230 of the first member 242. In the present embodiment the first andsecond coupling means 236, 238 extend outwards from the passageways ofthe first and second mounting means 222, 224. The first and secondcoupling means 236, 238 are received within the first and second toolengagement means 226, 227.

Referring to FIG. 11, the first member 242 includes a cylinder and thesecond member 244 includes a piston that is movable within the cylinder.Further, the first and second members 242, 244 may be fluidly coupled toa hydraulic circuit (not shown). The hydraulic circuit may be controlledby an operator to retract or extend the first and/or second members 242,244. In this embodiment, the hydraulic circuit may supply pressurizedhydraulic fluid to the cylinder formed within the first member 242, andmay force the piston formed in the second member 244 to extend withrespect to the first member 242. Further, a restriction to the flow ofhydraulic fluid from the cylinder restricts the movement of the firstmember 242, with respect to the second member 244, thereby locking theactuator 240 in the extended position thereof.

INDUSTRIAL APPLICABILITY

The present disclosure provides the coupling apparatus 128 forassembling the work tool 108 with the arm assembly 102 of the machine100. The present disclosure further provides a method 1200 forassembling the work tool 108 with the arm assembly 102. FIG. 12illustrates a flowchart of the method, according to an embodiment of thepresent disclosure. Further, the method 1200 may be implemented in anysuitable hardware, such that the hardware employed can perform the stepsof the method 1200 readily and on a real-time basis. For the conveniencein description, various steps of the method 1200 will be described inconjunction with the preceding figures of the present disclosure.

Referring to FIG. 12, at step 1202 of the method 1200, the firstcoupling means 236 is engaged with the first arm 106 of the arm assembly102 and first tool engagement means 226. In one example, the actuator240 is in a retracted position. The first coupling means 236 is alignedwith the first mounting means 222. The first coupling means 236 isreceived within first coupling means 236 and the first mounting means222. Further, the extended portions of the first coupling means 236 arecoupled with the first tool engagement means 226, particularly by beingreceived in the recesses as shown in FIG. 8. At step 1204 the secondcoupling means 238 is engaged with the second arm 216. The secondcoupling means 238 is aligned with the second mounting means 224. Thesecond coupling means 238 is received within the second mounting means224 as shown in FIG. 9.

At step 1206 the actuator 240 is moved to an extended position to engagethe second coupling means 238 to the second tool engagement means 227.The first member 242 of the actuator 240 is moved relative to the secondmember 244 along the longitudinal axis B-B′ to move into an extendedposition. The second coupling means 238 extends further to couple theextended portion of the second coupling means 238 to the second toolengagement means 228, particularly by being received within therecesses.

At step 1208, the locking sleeve 270 is moved to a locked position. Thelocking sleeve 270 is turned about the abutment portion 260 such thatthe second portion 274 conforms to the stop 252 of the first member 242as shown in FIG. 10. The locking sleeve 270 prevents any relative motionsuch as retraction between the first member 242 and the second member244 thereby coupling the work tool 108 to the machine 100. In the lockedposition one or more protrusions 276 of the locking sleeve 270 engageswith the stop 252 of the first member 242. Further, the locking sleeve270 and the stop 252 are arranged such that the motion of the lockingsleeve 270 is prevented in at least one direction. In an unlockedposition the protrusions 276 allows relative motion between the firstand the second member 242, 244. In one embodiment, the locking sleeve270 may be spring loaded such that the locking sleeve 270 turns to thelocked position when the first and second members 242, 244 are atextended position. In another embodiment the locking sleeve 270 may havea different mechanism to lock the actuator 240 such as push, slide,latch and the like.

Therefore, as it would be understood to the person skilled in the art,the coupling apparatus 128 of the present disclosure provides an easyand efficient coupling of the work tool 108 to the arm assembly 102.Since the coupling or the assembling of the work tool 108 and the armassembly 102 is assisted by the actuator 240 and the locking sleeve 270,the process of coupling can be performed in short duration of time.Further, owing to the presence of flexibility in placing the first andsecond tool engagement means 226, 227, the coupling apparatus 128 can bereplaced or coupled to the arm assembly 102 at any instant of time.Furthermore, since the coupling or the assembling of the work tool 108and the arm assembly 102 may be carried out by the actuator 240 andlocking sleeve 270, provided at the arm assembly 102, overall weight andlength of the arm assembly 102 remains substantially same, and thereforecapabilities of the machine 100 remain uncompromised.

While aspects of the present disclosure have been particularly shown anddescribed with reference to the embodiments above, it will be understoodby those skilled in the art that various additional embodiments may becontemplated by the modification of the disclosed machines, systems andmethods without departing from the spirit and scope of what isdisclosed. Such embodiments should be understood to fall within thescope of the present disclosure as determined based upon the claims andany equivalents thereof.

1. An apparatus for coupling a work tool to an arm assembly of amachine, the work tool including a first recess and a second recess, thearm assembly including a first arm and a second arm, the apparatusincluding: a first pin configured to engage with the first arm and thefirst recess; a second pin configured to engage with the second arm andthe second recess; an actuator coupled to the first pin and the secondpin and arranged to move between a retracted position, in which at leastone of the first pin and the second pin is disengaged from at least oneof the first recess and the second recess, and an extended position, inwhich the first pin and the second pin are engaged with the first recessand the second recess; and a locking sleeve mounted at least partiallyaround the actuator, the locking sleeve being moveable into a lockedposition to prevent the actuator from moving into the retracted positionfrom the extended position.
 2. An apparatus as claimed in claim 1,wherein the first recess includes a first hook and the second recessincludes a second hook.
 3. The apparatus of claim 2, wherein theactuator comprises a first member moveable relative to a second member,the locking sleeve being mounted at least partially around one of thefirst member and the second member.
 4. The apparatus as claimed in claim3, wherein the first member comprises a stop against which the lockingsleeve abuts when in the locked position.
 5. The apparatus as claimed inclaim 3, wherein the second member comprises an abutment portion againstwhich the locking sleeve abuts.
 6. The apparatus as claimed in claim 4,wherein the locking sleeve and the stop are arranged such that, when inthe locked position, rotation of the locking sleeve is prevented in atleast one direction.
 7. The apparatus as claimed in claim 3, wherein thefirst member comprises a cylinder and the second member comprises apiston moveable within the cylinder.
 8. The apparatus as claimed inclaim 1, wherein the locking sleeve includes: a first portion adapted toabut an abutment portion of the actuator; and a second portion extendingfrom the first portion, wherein the second portion includes one or moreprotrusions extending along the longitudinal axis of the locking sleeve,and wherein the locking sleeve is adapted to rotate about thelongitudinal axis between a locked position and an unlocked position. 9.The apparatus as claimed in claim 8, wherein the one or more protrusionsof the second portion of the locking sleeve engages with the stop of theactuator when the locking sleeve is in the locked position.
 10. Amachine, comprising: an arm assembly including a first arm and a secondarm; a work tool including a first recess and a second recess; and anapparatus configured to couple the work tool to the arm assembly, theapparatus comprising: a first pin configured to engage with the firstarm and the first recess; a second pin configured to engage with thesecond arm and the second recess; an actuator coupled to the first pinand second pin and configured to move between a retracted position, inwhich at least one of the first pin and the second pin is disengagedfrom at least one of the first recess and the second recess, and anextended position, in which the first pin and the second pin are engagedwith the first recess and the second recess; and a locking sleevemounted at least partially around the actuator, the locking sleeve beingmoveable into a locked position to prevent the actuator from moving intothe retracted position from the extended position.
 11. A method ofcoupling a work tool to an arm assembly of a machine, the work toolhaving a first recess and a second recess, and the arm assembly having afirst arm and a second arm, the method comprising: engaging a first pinwith the first arm and the first recess; engaging a second pin with thesecond arm; moving an actuator to an extended position to engage thesecond pin with the second recess; and, moving a locking sleeve to alocked position to prevent the actuator from moving into the retractedposition from the extended position.
 12. The method of claim 10, whereinthe step of moving the actuator includes moving a first member of theactuator relative to a second member of actuator.
 13. The method ofclaim 10, wherein the step of moving the locking sleeve includesrotating the locking sleeve around the actuator to abut against theabutment portion of the second member.
 14. The machine of claim 10,wherein the actuator comprises a first member moveable relative to asecond member, the locking sleeve being mounted at least partiallyaround one of the first member and the second member.
 15. The machine ofclaim 14 wherein the first member comprises a stop against which thelocking sleeve abuts when in the locked position.
 16. The machine ofclaim 14, wherein the second member comprises an abutment portionagainst which the locking sleeve abuts.
 17. The machine of claim 14,wherein the locking sleeve and the stop are arranged such that, when inthe locked position, rotation of the locking sleeve is prevented in atleast one direction.
 18. The machine of claim 14, wherein the firstmember comprises a cylinder and the second member comprises a pistonmoveable within the cylinder.
 19. The machine of claim 10, wherein thelocking sleeve includes: a first portion adapted to abut an abutmentportion of the actuator; and a second portion extending from the firstportion, wherein the second portion includes one or more protrusionsextending along the longitudinal axis of the locking sleeve, and whereinthe locking sleeve is adapted to rotate about the longitudinal axisbetween a locked position and an unlocked position.
 20. The machine ofclaim 19, wherein the one or more protrusions of the second portion ofthe locking sleeve engages with the stop of the actuator when thelocking sleeve is in the locked position.